Form lifter for box wrapping mechanism



July 29, 1941. E. G. RIDER FORM LIFTER FOR BOX WRAPPING MECHANISM Filed April 13, 1940 INVENTOR ERNEST G. RIDER ATTORNEY Patented July 29, 1941 LIFTER FOR BOX WRAPPING MECHANISM Ernest G. Rider; Philadelphia, Pa., assignor to Stokes and Smith Company, Summerdale, Pa., a corporation of Pennsylvania Application April 13, 1940, Serial No. 329,487

3 Claims.

The present invention relates to box wrapping mechanism and more particularly to an attachment for assisting an operator in separatingthe forming blocks. I

During the operation of wiping and folding a wrapper about a box it happens more or less frequently that portions of the wrapper adhere to the form blocks and obstruct proper operation of the machine until this material is scraped from the blocks. To remove this material the operator must support the upper form block with one hand while attempting to scrape in the small space between the blocks. This is an awkward and ineificient method and results in an appreciable loss of time in machine hours. v 7

Some of the objects of the present invention are to provide a novel attachment for box wrapping machines whereby easy access can be had to the working faces of the forming blocks; to provide means wherein provision is made for supporting the upper forming block of a box wrapping machine to allow an operator to use both hands in cleaning the forming blocks; to provide a supporting device for the upper block of a box wrapping machine which automatically becomes ineffective when the wrapping machine resumes operation after a stoppage; and to provide other improvements as will hereinafter appear.

In the accompanying drawing forming part of this description:

Fig. 1 represents a front elevation partly broken away of a portion of a box wrapping mechanism as equipped with one form of the present invention and showing the forming blocks in closed position;

Fig. 2 represents the same elevation showing the open position of the blocks after the device of the invention has been operated;

Fig. 3 represents a secton on line 33 of Fig. 4;

Fig. 4 represents a section on line 44 of Fig. l; and

Fig. 5 represents a detail of the lift cam.

Referring to the drawing, one form of the present invention as applied to a box wrapping machine of the general type shown in Letters Patent No. 691,329 wherein an upper form block W is suspended by side rods II in vertical alinement with a lower main former l2 which is car-- ried by a tubular plunger [3 and spur I l. The rods II and plunger l3 are arranged for vertical movement independent of each other and have related cycles of operation determined by separate cam or other mechanisms to carry out the required function. During the wrapping operations the form block ldrises as necessary to permit certain turn-in fingers to pass above the main former l2 and fold the upstanding ends and sides of the wrapper material into position to be wiped into the box by the lowering of the form block IE3 on its return stroke. This wiping and pressing action of the form block I0 frequently results in some of the wrapping material adhering to the block and this necessitates stopping the machine, raising the block Ill by hand and holding it up while the other hand of the operator scrapes and freesthe block of the ma.

terial. It is to this troublesome operation that the present invention is directed to result in greater simplified action and a maximum reduction of idle machine hours.

In order to lift the form. block l0 and its as sociated assembly independently of the normal power actuated means, a lift bar l5, preferably of flat bar stock, is provided having attached thereto at one end an offset tubular sleeve I6 which is fitted over one of the lift rods H and fixed thereto by a friction ring I! encircling the rod II and seating laterally in a circumferential groove I8 cut in the rod H in close proximity to a shoulder 20 formed by an enlargement of the diameter of the bore of the sleeve I6. The bar I 5 is disposed vertically edgewise and is long enough to extend from the rod ll through the plunger l3 where it is guided by oppositely disposed guide slots 2| cut vertically in the respec tive opposite sides of the aforesaid plunger. These slots l8 are sufiiciently longer than the width of the bar l5 to allow the proper relative motion of the rods II and plunger I3 when these parts are under control of the operating cams or other means. The fixed position of the lift bar l5 and the location of the slots 2| is such as not to interfere with or prevent any normal movements of the two forming blocks.

For the purpose of elevating the lift bar IS a cam 22 is eccentri'cally carried on the end of a rock spindle 23 which is journalled in a bearing bushing 24 fixed to and passing through one side of the plunger l3. A collar 25 abuts the plate 25, which anchors the bushing 24 in place, and is fastened to the spindle 23 by a set screw 21 to maintain the proper relation of the parts. An operating lever in the form of a hub 28 and two diametrically opposite arms 29 and 30, is fixed to the spindle 23 by a pin 3| or other fastening means to rock the spindle from one position to the other. Normally the cam 22 is in the position shown in Fig. 1 and in order that it return automatic-ally when the machine resumes operation, a counterweight is provided for the purpose. As shown this counterweight consists in making the lower arm 30 of the lever longer than the alined upper arm 29 and therefore when the heavier arm 30 is in its upper position and the machine shifts the plunger l3 to thereby release the cam, then gravity returns the lever to its normal position with the 'cam in its lower position. Preferably that face of the cam 22 which is furthest from the axis of rotation is formed with a seat 32 having sufficient area to abut the edge face of the lift bar I5 with just enough resistance to prevent Slight jars from prematurely releasing the lift bar 15 when in the position shown in Fig. 2.

The device is brought into operation whenever there is a clogging of the form blocks due to a wrapper jam. When this happens the machine is stopped, the operator grasps the lever and turns it through one hundred and eighty degrees. This movement swings the cam 22 upwardly to also lift the bar I5 and through it the rods II and upper form block [8 so that sufficient space is opened between the form blocks to permit proper access in order toremove jammed or stuck wrapping material. This operation can be carried out efficiently because both hands of the operator are free to correct the trouble since the cam 22 is in its uppermost position holding the hit bar ['5 seated thereon. As soon as the blocks are cleared, ready to resume operations, the machine is started whereupon the incident vibration shakes the counterweight arm. 30 from dead center position and thus swings the lever and cam 22 back to normal position.

While only a single form is shown in which this invention may be embodied, it is to be understood that the invention is not limited to any specific construction, but might be applied to various forms without departing from the spirit of the invention or the scope of the appended claims.

I claim as my invention:

1. In a mechanism for applying wrappers to boxes, the combination of an upper forming block, operating means for said block, a main forming block, a laterally disposed bar fixed to said operating means, a cam having a flattened surface arranged, when turned, to engage and lift said bar to elevate and temporarily lock said upper block from said main block, and means to actuate said cam.

2. In a mechanism for applying wrappers to boxes, the combination of an upper forming block, operating means for said block, a main forming block, a laterally disposed bar fixed to said operating means, a cam arranged, when turned, to engage and lift said bar to elevate said upper block from said main block, means to actuate said cam, and means comprising a substantially flattened area on said cam to support and temporarily to lock said bar in elevated position.

3. In a mechanism for applying wrappers to boxes, the combination of an upper forming block, operating means for said block, a main forming block, a laterally disposed bar fixed to said operating means, a cam arranged, when turned, to engage and lift said bar to elevate said upper block from said main block, and means including a two arm lever to actuate said cam, one arm of said lever being heavier than the other, said cam comprising a relatively flat area to support and temporarily to lock said bar in elevated position and arranged for automatic unlocking when the motion of the mechanism, moves the bar from contact with said fiat area of said cam.

ERNEST G. RIDER. 

